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Fungi in water pose great risk to immune-compromised individuals

24 July 2023 | Story André Damons | Photo Supplied

Yeast and other filamentous fungi, which pose a great risk to the health of immune-compromised or suppressed individuals, can be found in various drinking water sources such as ground, spring, surface, and tap water. These opportunistic pathogens may cause severe to fatal infections and can range from superficial to bloodstream or systemic infections.

This is according to Tyla Baker, a postgraduate student in the Department of Microbiology and Biochemistry at the University of the Free State (UFS). She is studying for her MSc degree in Microbiology under the supervision Prof Carlien Pohl-Albertyn, National Research Forum (NRF) SARChI Research Chair in Pathogenic Yeasts. Prof Jacobus Albertyn and Dr Jolly Musoke are her co-supervisors.

Baker says the fungi in the water highlights that current water treatment processes are not efficient in their removal from water destined for household use. “These infections may not be harmful to people with healthy immune systems, but do pose a great risk to the health of immune-compromised or suppressed individuals.

Definite possibility to contract fungal infections from polluted water

“As the number of people with immune systems that are less functional (e.g. premature babies, elderly persons, people with cancer, diabetes or other serious diseases, HIV+ persons, transplant patients) increases, the number of people at risk of fungal infection also increases,” says Baker.

According to Baker, a previous study done in Brazil has identified yeast in bottled mineral water as well as municipally supplied tap water. The potential risk to contract fungal infections from polluted water sources is a definite possibility but more research is required to fully understand and determine the level of risk and the extent of its effects, she says. In the context of Mangaung, it is a concern that untreated water from sewage works as well as other sewage often leaks into the environment (as evidenced by numerous recent articles in local newspapers). These waters are potential carriers of large numbers of pathogens (including pathogenic yeasts/fungi) that may increase the risk to people coming into contact with it.

Baker says there is a good chance people are consuming these kinds of micro-organisms daily, considering that yeast and other filamentous fungi can also form biofilms inside pipes and spread as the impact of water flow dislodges these cells. “People will not even be aware that they are consuming these micro-organisms, some fungi are considered nuisance microbes and may cause a change in the smell and taste of water which may act as an indicator that the water is contaminated, but tests would be needed to confirm this,” she says.

The effects of consuming these fungi are still a grey area of research since the full extent of the consumption of yeast is still unknown, but there are studies being conducted to elucidate the full impact of this occurrence, says Baker. The risk depends on the immune status of the person, the specific species of yeast/fungus ingested, and the number of cells/spores ingested.

Culture-dependent and independent methods

“It is important to know that many pathogenic yeasts and other fungi are opportunistic pathogens, meaning they infect individuals whose immune systems are compromised due to various reasons such as illness (HIV/AIDS, cancer, TB etc.), undergoing organ transplants or even something as simple as using antimicrobial agents such as antibiotics.

“Taking this into account, along with the HIV/AIDS statistics in South Africa, which has a prevalence rate of 13,7% with approximately 8,2 million people in 2021 living with HIV, these individuals are more susceptible to infection by these opportunistic pathogens. Some of these pathogenic yeasts are also multidrug resistant or show resistance to readily available antifungals, such as fluconazole, which hinders the ability of healthcare professionals to efficiently treat infections to avoid fatal/severe outcomes,” explains Baker.

For her studies, she will be testing for fungi in water by using a combination of culture-dependent and independent methods to try and identify yeast present in wastewater. Baker says culture-dependent techniques will include culturing (growing) yeast on an appropriate medium while culture-independent techniques will include more intricate molecular work in the form of a multiplex PCR (polymerase chain reaction) which will enable her to identify an array of pathogenic yeasts present in samples.

According to Baker, people can stay safe by boiling water before drinking it, although temperatures above 100°C are required to kill most harmful microbes. Regular cleaning of shower heads and faucets help to prevent build-up which may act as a surface to which fungi will attach to and grow. Another way to stay safe is to maintain and regularly inspect water filters for damage and avoid contact with untreated sewage.

News Archive

Eye tracker device a first in Africa

2013-07-31

31 July 2013

Keeping an eye on empowerment

"If we can see what you see, we can think what you think."

Eye-tracking used to be one of those fabulous science-fiction inventions, along with Superman-like bionic ability. Could you really use the movement of your eyes to read people's minds? Or drive your car? Or transfix your enemy with a laser-beam?

Well, actually, yes, you can (apart, perhaps, from the laser beam… ). An eye tracker is not something from science fiction; it actually exists, and is widely used around the world for a number of purposes.

Simply put, an eye tracker is a device for measuring eye positions and eye movement. Its most obvious use is in marketing, to find out what people are looking at (when they see an advertisement, for instance, or when they are wandering along a supermarket aisle). The eye tracker measures where people look first, what attracts their attention, and what they look at the longest. It is used extensively in developed countries to predict consumer behaviour, based on what – literally – catches the eye.

On a more serious level, psychologists, therapists and educators can also use this device for a number of applications, such as analysis and education. And – most excitingly – eye tracking can be used by disabled people to use a computer and thereby operate a number of devices and machines. Impaired or disabled people can use eye tracking to get a whole new lease on life.

In South Africa and other developing countries, however, eye tracking is not widely used. Even though off-the-shelf webcams and open-source software can be obtained extremely cheaply, they are complex to use and the quality cannot be guaranteed. Specialist high-quality eye-tracking devices have to be imported, and they are extremely expensive – or rather – they used to be. Not anymore.

The Department of Computer Science and Informatics (CSI) at the University of the Free State has succeeded in developing a high-quality eye tracker at a fraction of the cost of the imported devices. Along with the hardware, the department has also developed specialised software for a number of applications. These would be useful for graphic designers, marketers, analysts, cognitive psychologists, language specialists, ophthalmologists, radiographers, occupational and speech therapists, and people with disabilities. In the not-too-distant future, even fleet owners and drivers would be able to use this technology.

"The research team at CSI has many years of eye-tracking experience," says team leader Prof Pieter Blignaut, "both with the technical aspect as well as the practical aspect. We also provide a multi-dimensional service to clients that includes the equipment, training and support. We even provide feedback to users.

"We have a basic desktop model available that can be used for research, and can be adapted so that people can interact with a computer. It will be possible in future to design a device that would be able to operate a wheelchair. We are working on a model incorporated into a pair of glasses which will provide gaze analysis for people in their natural surroundings, for instance when driving a vehicle.

"Up till now, the imported models have been too expensive," he continues. "But with our system, the technology is now within reach for anyone who needs it. This could lead to economic expansion and job creation."

The University of the Free State is the first manufacturer of eye-tracking devices in Africa, and Blignaut hopes that the project will contribute to nation-building and empowerment.

"The biggest advantage is that we now have a local manufacturer providing a quality product with local training and support."

In an eye-tracking device, a tiny infra-red light shines on the eye and causes a reflection which is picked up by a high-resolution camera. Every eye movement causes a change in the reflection, which is then mapped. Infra-red light is not harmful to the eye and is not even noticed. Eye movement is then completely natural.

Based on eye movements, a researcher can study cognitive patterns, driver behaviour, attention spans, even thinking patterns. A disabled person could use their eye-movements to interact with a computer, with future technology (still in development) that would enable that computer to control a wheelchair or operate machinery.

The UFS recently initiated the foundation of an eye-tracking interest group for South Africa (ETSA) and sponsor a biennial-eye tracking conference. Their website can be found at www.eyetrackingsa.co.za.

“Eye tracking is an amazing tool for empowerment and development in Africa, “ says Blignaut, “but it is not used as much as it should be, because it is seen as too expensive. We are trying to bring this technology within the reach of anyone and everyone who needs it.”

Issued by: Lacea Loader
Director: Strategic Communication

Telephone: +27 (0) 51 401 2584
Cell: +27 (0) 83 645 2454
E-mail: news@ufs.ac.za
Fax: +27 (0) 51 444 6393

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